Time dependence of measured surface tension is determined by dynamic surface tension evolution given by physical processes, and finally by chemical changes of material during measurement.
Static surface tension values are commonly used, while their measured values are often in fact dynamic surface tension of the surface of non-zero age, sometimes not exactly known. Dynamic surface tension is result of more processes; some of them were well explored, others open up scientific work to be done. Several equations based on different controlling processes were published for dynamic surface tension in time.
A student should, after learning the problem, take part in determination, which of published models describe best the dynamic surface tension in individual materials under different condition, and in determination of parameters of related equations. Then, development of own theories and models describing complex of processes determining dynamic surface tension including their verification is expected from the student.
Knowledge of physical chemistry is expected. Since modification of measuring software will be necessary, skills in work with C programming language are required. Then, knowledge or willingness to learn to work with data fitting to complicated nonlinear equations is expected.